Vitamin D is Absorbed Better with Fat

I have updated the article, Calcium and Vitamin D, to reflect recent research showing that vitamin D supplements are better absorbed when taken with meals that contain fat.

The study was a randomized controlled trial conducted at Tufts University (1). It compared taking a 50,000 IU dose of vitamin D3 with three different meals: 1) a fat-free meal, 2) a 30% fat meal with high polyunsaturated fats, 3) a 30% fat meal with high monounsaturated fats. To make a short story even shorter, the meals with fat increased vitamin D absorption 32% over the meals without. There was no difference between meals high in polyunsaturated and monounsaturated fats.

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1. Dawson-Hughes B, Harris SS, Lichtenstein AH, Dolnikowski G, Palermo NJ, Rasmussen H. Dietary fat increases vitamin D-3 absorption. J Acad Nutr Diet. 2015 Feb;115(2):225-30. | link

8 Responses to “Vitamin D is Absorbed Better with Fat”

  1. daisy Says:

    How do you think this study relates to vitamin D2, since D3 isn’t vegan?

  2. Jack Norris RD Says:


    I’m not aware of vitamin D2 being less fat-soluble than D3 so I would assume these results would apply to D2.

  3. phuzzie Says:

    daisy, vegan vitamin D3 supplements are available these days, derived from lichen, e.g.,

    Also you can get fungus exposed to UV radiation to produce D3, even doing so yourself.

  4. Jack Norris RD Says:

    Oops, I meant to tell daisy about the vegan D3.

    But phuzzie, I’m pretty sure you can only make D2 from exposing mushrooms to UV radiation–the article you link to seems to be in agreement with that.

  5. Hubert R Says:

    Hi Jack,

    My father sent me some text about D2 being inferior to D3. I started to search, there is a link to pubmed of the original research. I didn’t found it on veganhealth, so perhaps you’ll find it interesting, and can share your thoughts about it 🙂

  6. Jack Norris RD Says:


    I have a copy of that study and what the abstract doesn’t say is that 25(OH)D levels went up 30 nmol/L in the vitamin D2 group. This wasn’t as much as the vitamin D3 group in which 25(OH)D levels went up 46 nmol/L. Changes in PTH were not statistically significant. The vitamin D2 group’s 25(OH)D levels went to an average of 67.8 nmol/L which is above the lower limit of healthy at 50 nmol/L. Recommended levels by the Institute of Medicine are 50-125 nmol/L. Average 25(OH)D levels for people taking vitamin D3 were 89.2 nmol/L.

    So it appears that over the course of 8 weeks, vitamin D3 increased levels more than D2, but D2 might be sufficient. I don’t think it’s enough evidence to warrant only taking vitamin D3, especially since other studies have also shown D2 to be sufficient.

  7. Jack Norris RD Says:


    A bit more info:

    Vitamin D3 Performs Slightly Better Than D2 in Clinical Trial

  8. Hubert Says:

    Ok, thank you very much for clarification!

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